One vertex per element, one color per generator, with an edge from x to x·s.
(10,14)(15,21)(16,19)(22,23)(25,26)(27,30)(28,39)(29,31)(32,37)(33,36)(34,38)(35,40) involution — undirected(1,2)(3,6)(4,7)(5,8)(9,10)(11,15)(12,16)(13,14)(17,22)(18,21)(19,20)(23,24)(25,27,32,36)(26,33,37,30)(28,31,38,35)(29,39,40,34)(1,3)(2,5)(4,8)(6,7)(25,28)(26,34)(27,31)(29,33)(30,40)(32,38)(35,36)(37,39) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,10)(11,15)(12,19)(13,14)(16,20)(17,23)(18,21)(22,24)(25,29,32,40)(26,35,37,31)(27,34,36,39)(28,33,38,30)(9,11,13,18)(10,15,14,21)(12,17,20,24)(16,22,19,23)(25,30,32,33)(26,36,37,27)(28,40,38,29)(31,34,35,39)(1,2)(3,5)(4,7)(6,8)(9,12,13,20)(10,16,14,19)(11,17,18,24)(15,22,21,23)(25,31,32,35)(26,29,37,40)(27,38,36,28)(30,34,33,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.